This invention is generally concerned with pipeline devices that are flange mounted and specifically with such devices that have loosely secured flanges. As is well known, flanges are utilized to secure valve bodies, pipes and the like in abutting relationship in pipeline systems. Flanges are generally categorized as integral or separable depending upon whether they are an integral part of the valve body or pipe assembly or are separate and loosely attached thereto. The invention is directed to separable flanges which are generally required to be laterally and rotationally movable with respect to the pipeline assembly or valve body for installation purposes. Such flanges may be secured to their valve body by any number of well known means, including split retention rings that nest in suitable retention grooves.
In U.S. Pat. No. 4,767,138, a novel hubless flange is described and claimed. That flange is secured to a pipeline device by means of a split ring and a retention groove in the device. The retainment system of the invention is described in connection with that flange and a suitable valve body, but it should be understood that other types of pipeline devices and flanges may also benefit from the invention.
A difficult problem is that in installing heavy valves and other pipeline devices, there is a need for a number of people to guard against the parts slipping or rotating while the line bolting is being installed. Prior art flanges require three or more people to assure a degree of safety in working on such heavy pipeline equipment. Another consideration is the need to retain the capability of changing flange gaskets in the field which requires that the separable flange be laterally moved on the pipeline device or valve body. This need for lateral movement is a detriment during installation and the ability of the separable flange mechanism to laterally move also contributes to safety concerns.
With the retainment system of the invention, a simple low cost arrangement is provided for securing the separable flange from both lateral and rotational movement with respect to the body of the pipeline device.